The following relates to the medical arts, information arts, and related arts. It finds application in preclinical studies, in clinical studies, in medical diagnosis and monitoring, and the like.
Medical studies synthesize information from numerous sources. Within a study, various types of information may be generated and synthesized, such as: medical images or other in vivo data; in vitro data such as tests on drawn blood, mass spectrum profiles or the like; ex vivo data such as histology findings; and so forth. Additionally, a medical study may synthesize outside information such as the procedures used in, and results obtained by, similar studies. The information synthesis reviews “comparable” information to detect trends, similarities, or other commonalities possibly indicative of an underlying common pathology or other common condition, and to detect differences or dissimilarities that may contraindicate a common condition or may point to some underlying additional complexity that may impact the findings of the study.
The comparisons should involve “comparable” information. For example, two images may be comparable if they are of the same anatomical region and are acquired using similar geometry and at similar resolution. Any differences between the images, such as different modalities (e.g., comparison of a magnetic resonance image and a computed tomography image), must be considered in making a valid comparison. Since image geometries may not be identical, a registration algorithm may be applied to spatially align corresponding features of images under comparison. Temporal registration may also be performed for comparisons of temporal sequences of images such as cardiac CINE image sequences.
To facilitate making valid comparisons, image information annotations may be stored with the image. Typically, medical images are stored in a database such as a Picture Archive and Communication System (PACS) in a standard format such as the Digital Imaging and Communication in Medicine (DICOM) format promulgated by the National Electrical Manufacturers Association (NEMA, Rosslyn, Va.), or variants of the promulgated format (such variants also sometimes referred to as a DICOM format). The DICOM format includes the image data along with a DICOM header storing information about the image such as modality, resolution, subject identification information, subject demographic information, cataloging information identifying the study or other grouping of which the image is a part, information on any JPEG or other type of image compression or formatting (called “transfer syntax” information in the DICOM standard), modality-specific image acquisition information (such as the echo time, TE, in the case of magnetic resonance images), or so forth.
The DICOM header provides information about the image, which facilitates fair comparison of different images. However, the researcher performing an image comparison must still take care to ensure that the images are comparable respective to other factors, such as post-acquisition image processing operations that may have been performed on the image. Post-acquisition image processing may include, for example, image registration, image segmentation, contrast enhancement, or so forth. Over the course of a given study, the post-acquisition image processing workflow may be altered to improve detection of lesions or other clinically relevant features, or for other reasons. To ensure fair comparisons, such alterations must be taken into account when comparing images modified by different workflows. Comparisons with images from other studies can be even more problematic, since information on the post-acquisition image processing used in other studies may be difficult or impossible to obtain.
In some instances, it would be useful for the researcher to readily locate comparable images from other studies. For example, when a researcher encounters an unusual image that deviates strongly from other images of the study, the researcher will want to understand this deviant image. Understanding might be facilitated by comparison with similar images obtained in other studies. Unfortunately, merely identifying a visually similar image in the PACS database (or elsewhere) is insufficient for a fair comparison. This is true even if the information about the images provided by the DICOM headers is similar. Rather, once a visually similar image is identified in the DICOM database, the researcher must track down the post-acquisition processing workflow (if any) performed on the identified visually similar image in order to determine whether it is fairly comparable with the deviant image of the present study.
The following provides a new and improved apparatuses and methods which overcome the above-referenced problems and others.